Displaying 20 results from an estimated 1000 matches similar to: "Cox model: random effect on a variable with 3 levels"
2009 Oct 01
0
General mixed effects Cox models
After an extremely long gestation, a new version of the coxme package is
now available on CRAN. This function fits very general mixed-effects
Cox models using an lmer-like syntax. For instance here is a model that
fits a random treatment effect, using data from a multi-study
collaboration.
fit <- coxme(Surv(pg.time, pg.stat) ~ stage + trt + (trt|site) +
stata(site), data=
2009 Oct 01
0
General mixed effects Cox models
After an extremely long gestation, a new version of the coxme package is
now available on CRAN. This function fits very general mixed-effects
Cox models using an lmer-like syntax. For instance here is a model that
fits a random treatment effect, using data from a multi-study
collaboration.
fit <- coxme(Surv(pg.time, pg.stat) ~ stage + trt + (trt|site) +
stata(site), data=
2010 Aug 22
2
coxme AIC score and p-value mismatch??
Hi,
I am new to R and AIC scores but what I get from coxme seems wrong. The AIC
score increases as p-values decrease.
Since lower AIC scores mean better models and lower p-values mean stronger
effects or differences then shouldn't they change in the same direction? I
found this happens with the data set rats as well as my own data. Below is
the output for two models constructed with the rats
2010 Mar 05
2
Defining a method in two packages
The coxme package has a ranef() method, as does lme4. I'm having
trouble getting them to play together, as shown below. (The particular
model in the example isn't defensible, but uses a standard data set.)
The problem is that most of the time only one of lme4 or coxme will be
loaded, so each needs to define the basic ranef function as well as a
method for it. But when loaded together
2015 Mar 02
1
clarification on import/depends for a method
User of the coxme library (mixed effects Cox models) are instructed to use ranef(),
fixed(), VarCorr(), etc to retrieve bits out of a fitted model; it purposely uses the same
methods as nlme and/or lmer.
The current behavior is to "depend" on nlme. If I defined the methods myself in coxme,
then someone who had both nlme and coxme loaded will suffer from "last loaded wins",
2015 Feb 16
0
Imports problem
> > I'm testing out a new version of coxme and R CMD check fails with "could not find function
> > ranef" (or random.effects or fixef, or anything from nlme). The NAMESPACE file has the
> > line below
>
> > importFrom(nlme, ranef, random.effects, fixef, fixed.effects, VarCorr)
>
> > and nlme is declared in the DESCRIPTION
2011 Dec 30
0
New version of coxme / lmekin
Version 2.2 of coxme has been posted to CRAN, Windows versions and
mirrors should appear in due course. This is a major update with three
features of note:
1. A non-upwardly compatable change:
Extractor functions: beta= fixed effects, b=random effects
nlme lme4 coxme <2.2 coxme 2.2 lmekin 2.2
------------------------------------------------------
beta
2015 Feb 16
2
Imports problem
On 16/02/2015 8:20 AM, Therneau, Terry M., Ph.D. wrote:
>
>> > I'm testing out a new version of coxme and R CMD check fails with "could not find function
>> > ranef" (or random.effects or fixef, or anything from nlme). The NAMESPACE file has the
>> > line below
>>
>> > importFrom(nlme, ranef, random.effects, fixef,
2015 Feb 16
0
Imports problem
>>>>> Therneau, Terry M , Ph D <therneau at mayo.edu>
>>>>> on Sun, 15 Feb 2015 17:31:00 -0600 writes:
> I'm testing out a new version of coxme and R CMD check fails with "could not find function
> ranef" (or random.effects or fixef, or anything from nlme). The NAMESPACE file has the
> line below
>
2005 Nov 06
2
cox models
Hello,
i'm a french student of medical oncology and i'm working on breast
cancer. I have a variable with the histologic type of tumor wich is
between 1 and 5. I use as.factor function to make some variable with
level between 1 and 5. When i put it in the cox model i have only the
level between 2 and 5. The level 1 doesn't appear. I think i have to
change the number of level but i
2013 Feb 14
1
Nomogram after Cox Random Effect (frailty) model
Dear R-users,
I am a novice R-user with some experience in using the RMS package for taking nomograms after various survival models.
This time, I am trying to plot a nomogram after a Random Effects Cox, implemented by the "coxme" package. My questions are:
1. Is it possible to take a nomogram directly after the coxme survival function?
2. If not is there a way to take the linear
2010 Mar 19
0
(no subject)
The change has also been made to coxme. I'm in the midst of another fix
(should be done by tomorrow) and will get posted to Rforge as soon as
that's done.
Terry
On Thu, Mar 18, 2010 at 6:26 AM, Dieter Menne
<dieter.menne at menne-biomed.de> wrote:
> I am trying to use nlme and coxme in one Sweave document. I have read
the
> thread in r-devel on the subject,
>
>
2010 Nov 02
2
multi-level cox ph with time-dependent covariates
Dear all,
I would like to know if it is possible to fit in R a Cox ph model with
time-dependent covariates and to account for hierarchical effects at
the same time. Additionally, I'd like also to know if it would be
possible to perform any feature selection on this model fit.
I have a data set that is composed by multiple marker measurements
(and hundreds of covariates) at different time
2015 Feb 15
2
Imports problem
I'm testing out a new version of coxme and R CMD check fails with "could not find function
ranef" (or random.effects or fixef, or anything from nlme). The NAMESPACE file has the
line below
importFrom(nlme, ranef, random.effects, fixef, fixed.effects, VarCorr)
and nlme is declared in the DESCRIPTION file as an import. I feel that I must be staring
at some obvious (but
2010 Nov 17
0
Cox model output & hazard ratios
Dear R users,
Here is the coxme output I obtain on my survival dataset having 3 strains
and 2 infection status (i: infected, ni: non infected)
coxme(Surv(lay) ~ infection*strain, data=datalay, random= ~1 |block)
Cox mixed-effects model fit by maximum likelihood
Data: datalay
n= 1194
Iterations= 3 77
NULL Integrated Penalized
Log-likelihood -7270.028 -7223.859 -7218.175
2005 Oct 25
0
One more about Error in step() (or stepAIC) for Cox model
Thank you for Prof.Ripley's suggestion. I fixed the program by adding a
lower scope, and the program ran, but I still got warning messages, and
don't know what is going on, would this affect my results?
...
Step: AIC= 12337.74
Surv(tlfup, cen) ~ MI[[j]]$trt + MI[[j]]$agem40 + MI[[j]]$agem40sq +
mhtypeed1 + mhtypeed2
Df AIC
<none> 12338
-
2012 Jul 18
0
Building a web risk calculator based on Cox, PH--definitive method for calculating probability?
Here is an example of how to do it.
> library(survival)
> vfit <- coxph(Surv(time, status) ~ celltype + trt, data=veteran)
> userinput <- data.frame(celltype="smallcell", trt = 1)
> usercurve <- survfit(vfit, newdata=userinput) #the entire predicted
survival curve
> user2 <- summary(usercurve, time= 2*365.25) # 2 year time point
> user2$surv
[1]
2012 Feb 03
1
coxme with frailty--variance of random effect?
Dear all,
This probably stems from my lack of understanding of the model, but I
do not understand the variance of the random effect reported in coxme.
Consider the following toy example:
#------------------------------- BEGINNING OF CODE
------------------------------------------------
library(survival)
library(coxme)
#--- Generate toy data:
d <- data.frame(id = c(1:100), #
2012 Jul 17
0
Building a web risk calculator based on Cox PH--definitive method for calculating probability?
Hello all,
I am a medical student and as a capstone for my summer research project I am
going to create a simple online web "calculator" for users to input their
relevant data, and a probability of relapse within 5 years will be computed
and returned based on the Cox PH model I have developed.
The issue I'm having is finding a definitive method/function to feed the
user's
2012 Apr 16
0
warning message: coxme with package multcomp
Hi
I'm encountering an error/warning when doing multiple comparisons with
the package multcomp on a coxme model.
My data:
I'm looking at the removal of brood from the nest according to three
treatments I applied on the brood.
The brood and the workers caring about the brood in the nest, belonged
to different colonies.
Factor: treatment (3 levels: tx,uv,meta)
Random effect 1: origin of